Lithosphere dynamics and present-day deformation pattern in the Pannonian basin
Abstract
We present new constraints and models on the dynamics and deformation pattern of the late-stage (Quaternary) tectonic inversion of the Pannonian basin system. The focus of the research is put on the analysis of the interplay between lithospheric processes, active tectonics and topography evolution using a whole basin scale approach. Our principal aim is to establish a framework and to provide a solid basis for ongoing neotectonic investigations targeting the understanding and quantification of tectonic processes that control landform evolution and related natural hazard. Neotectonic investigation and geoprediction in this actively inverting sedimentary basin requires multidisciplinary efforts and, therefore, the interaction and collaboration of researchers and a number of research institutes have been of vital importance. Numerical stress models suggest that the state of recent stress in the Pannonian basin, particularly in its western part, is controlled by the interplay of plate boundary forces, i.e., the counterclockwise rotation and northward indentation of the Adriatic microplate against the Alpine-Dinaric belt, and buoyancy forces associated with the irregular topography and related crustal thickness variation in and around the basin system. Tectonic units are currently displaced along major transform faults that are mainly reactivated structures of Miocene origin. Their internal deformation is manifested (1) in the late-stage subsidence anomalies of the entire basin system manifested in differential vertical movements and (2) the presence of a set of seismoactive shear zones imaged by a combined analysis of high-resolution seismic profiling and earthquake epicentre distribution. Stresses of a few tens of MPa accumulated in the thermally weakened Pannonian basin appears to be sufficient to cause large-scale folding of the inverting Pannonian lithosphere consistent with the pattern of present-day vertical deformation. Differential vertical motions in the form of basement uplift and basin subsidence indicate folding of the crust/lithosphere with a wavelength of a few tens to >100 kms. As a major result, a map of seismoactive faults for the actively inverting Pannonian basin is presented that was compiled with the aid of historical and modern seismicity data, a vast set of reflection seismic profiles and structural field data.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....5772B